The present invention generally relates to technology for generating a two-dimensional image by subjecting an event set in a virtual three-dimensional space to perspective projection transformation, and in particular relates to image processing technology for representing numerous spectators in a game device or the like relating to sports.
Pursuant to the development of computer technology in recent years, image processing technology relating to TV game machines and simulators (simulation rides) is becoming universally prevalent. In this kind of system, the rich expression of images to be displayed is key in increasing the commercial value. For instance, in a TV game machine related to sports such as soccer, it is desirable to realistically express the behavior of sports players to be operated by a player as well as realistically express the behavior of the attending spectators in order to further increase the commercial value (refer to Japanese Patent Laid-Open Publication No. H11-73525).
Meanwhile, in order to colorfully present the representation of spectators as described above, it is desirable to arbitrarily change the status of spectators according to various elements such as the association with the opposing team, number of spectators, and status of the stadium. Conventionally, in order to fulfill the foregoing demand, a plurality of textures created according to various situations were prepared, and a certain texture was selected for each game and attached to a polygon in order to display the spectators. Nevertheless, the advance preparation of textures according to all assumable situations of spectators (number of spectators, ratio of type of spectators, etc.) would entail a problem of significantly increasing the burden on the designer to create such textures, and increasing the data volume to be used in generating images.